Overview of the Toxic Substances Hydrology Program role in investigating the occurrence and fate of agricultural chemicals with links to investigations, headlines, on-line fact sheets, new publications, bibliographies and photo gallery.

Using genetic analysis of organic material found in aquatic environments it is possible to detect the presence of organisms without necessarily observing or capturing individuals. Explains terms, methods, and prospective utility of this approach.

Using ground-water geochemical analyses, and mathematical models, the factors affecting the quality of public water supply were identified as pumping schedule, screened interval, past land use within the recharge area, and natural geochemical conditions.

Using ground-water geochemical analyses and mathematical models, the factors affecting the quality of public water supply were identified as mixing of very recent recharge with older water, karst features, natural geochemical processes, and pumping.

Well vulnerability results from the young age of groundwater. Karst features permit contaminants to move into the aquifer easily, leading to a well mixed aquifer; geochemical processes do not degrade contaminants quickly.

Maps and text (Word or PDF format) and database (Excel or HTML format) for bedrock, forest floor, and mineral soil sampling in Voyageurs National Park, Minnesota to establish the background and baseline geochemistry and terrestrial mercury sources.

Homepage for the Biochemistry and Physiology Branch in Columbia, MO, which develops analytical techniques (cell bioassay/immunoassay) on toxicity related to fish and wildlife; and conducts research in microbiology and physiology.

Report of research on the Carolina slate belt and gold deposits in Virginia, North Carolina, South Carolina, and Georgia with geologic mapping, mineralogic, geochemical, and fluid evolution studies, radiogenic dating, and stable isotope studies.

Shows how coral reef specimens are collected, the type of information gained from them, and the methods by which they are measured and studied to understand recent (past few centuries) changes in climate.

Overview of the Core Research Center (CRC) in Denver for preserving valuable rock cores for permanent storage and making the cores available for examination and testing. Includes links to services, well reports, and resources.

Explains the important paleoclimatic information we have obtained from this subaqueous cavern. The time-series data show important contrasts with what would be predicted from orbital theory, provoking extensive scientific discussion.

By measuring the current and historical growth rates of coral skeletons, and using field experiments, we intend to find out whether rising atmospheric CO2 and rising sea levels will cause coral reefs to erode and cease to function.

Report describing the results of an interdisciplinary environmental study of the World Trade Center (WTC) area after the attack on September 11, 2001. The investigations included imaging spectroscopy mapping and laboratory analysis.

Direct measurement of an important indicator of interannual variability is extended, using geological proxy measures, farther back in time to well before modern measurements were made. This tells us about the history of climate variability.

Constructed farm ponds represent significant breeding, rearing, and overwintering habitat for amphibians in the Driftless Area Ecoregion of Minnesota, Wisconsin, and Iowa. Links to fact sheet, brochure, annual reports, field manual, and final report.

Highlights research studies involving genetics and genomics, includes a glossary of terms on the subject, a directory of scientists involved in this type of work, and description of research facilities through which USGS carries out genetic studies

Describes the value of molecular biology genetic tools in enhancing the delineation of the genetic diversity and the effects of environmental degradation on living species. Links to research, which differentiated two species of sage-grouse.

Site to obtain currently available geochemical reference materials, certificates for reference materials no longer available, reference materials in production, and order and processing information. Some documents in PDF format.

Services available at the Geological Survey TRIGA Reactor (GSTR) site in Denver with information on irradiation, neutron activation analysis, fission track radiography, and geochronology and tours of the facility.

The occurrence of solvents in the groundwater is not correlated with current overlying land use and human activities. Rather, the solvents are from legacy industrial uses, and it has taken decades for the groundwater to move to where it is now pumped.

Vanadium and boron were detected at high and moderate concentrations in this area. High concentrations for these constituents were detected almost exclusively in samples collected in the Temecula Valley study area.

Explanation of how geologists date rocks (to determine the ages of the Earth, fossils, mineral deposits, and other geologic events) and processes using radiometric dating techniques based on radioactive isotopes of carbon and potassium/argon.

Report presents an abridged guide for laboratory technicians and students using X-ray powder diffraction methodology to study crystalline structure and to determine the mineralogy of finer grained sediments, especially clays.

Brief overview of luminescence dating is presented, including a description of the method, its uses, and proper sample collection techniques. Links to other U.S. laboratories for luminescence dating are also provided.

Description of the work on paleomagnetism at the USGS Rock Magnetics Laboratory in Menlo Park, California with an overview of geomagnetic polar reversals, paleosecular variation, intensity, magnetic susceptibility, and rock magnetism analysis.

Special handling must be used because these one-celled organisms break down easily if dried, and the scientific analysis is enhanced by identifying smaller specimens. Shows how they are sampled, prepared, and studied using optical and electon microscopy.

Plan for an upcoming study, at the microbiological scale, of the benthic communities (including corals) that reside in and around mid-Atlantic canyons, which are located at the edge of the continental shelf.

Description of project monitoring the status of Greater Glacier National Park Area's grizzly bear and black bear populations using genetic techniques on DNA from bear hair or scats without handling bears, with photos and discussion of methods.

This report presents geochemical data generated during mineral and environmental assessments for the Bureau of Land Management in northern Nevada, northeastern California, southeastern Oregon, and southwestern Idaho, along with metadata and maps.

The U.S. National Ice Core Laboratory (NICL) is a facility in the Denver Federal Center, Colorado, for long-term storage, curating, and studying ice cores recovered from the polar regions of the world with information on public tours.

Homepage for description of the National Stream Quality Network (NASQAN), a long-term program monitoring the concentrations and flux of sediment and chemicals in the Nation's largest rivers (Mississippi, Columbia, Colorado, Rio Grande, and Yukon).

Summary of protocols describing procedures for laboratory analysis of algae samples collected by the U.S. Geological Survey's National Water Quality Assessment Program (NAWQA). Includes full document to be downloaded in PDF format.

Program to compile data from the National Water-Quality Assessment Program study units to study national trends with links to sediment coring sites, video on Salt Lake City, study units identification, and publications.

The National Wildlife Health Center (NWHC) is a biomedical laboratory assessing the impact of disease on wildlife and identifying the role of various pathogens in wildlife losses. Site has links to news, programs, publications and metadata.

Field manual (also available in PDF and paper formats) with instructions on techniques to collect and process water samples and to perform measurements of temperature, oxygen content, conductance, pH, turbidity, and fecal contaminants.

The area contributing recharge to this aquifer is undergoing rapid growth, generating more wastewater. We found that nitrate, a major component of wastewater and a nutrient that can degrade water quality, has increased in the creeks in this area.

Project to assess the grizzly bear population size, trend, and survival in the Northern Continental Divide Ecosystem (NCDE) in Montana to improve the long-term survival for this threatened species. With description, DNA identification means and photos.

Branch of Quality Systems monitors the consistent collection and reporting of water-quality data with documentation of field and laboratory methods and proficiency testing. Links to standard reference samples and quality assurance standards.

Site for the Optical Science Laboratory specializing in expert calibration of aerial mapping cameras with links to fees, scheduling cameras for calibration, historical camera database files, USGS aerial camera specifications, and how to visit.

In all, 56 compounds were detected in samples collected approximately monthly during 2003-05 at the intake for the Clackamas River Water plant. On the basis of this screening-level assessment, adverse effects to human health are assumed to be negligible.

Description of the Denver Organic Geochemistry Laboratory where chemical and geological data is used to research the physical and chemical processes of hydrocarbon generation, migration and accumulation, with links to programs, personnel, and products.

The Organic Geochemistry Research Group of the Kansas District focuses on the fate and transport of organic contaminants in the environment with links to objectives, analytical methods, laboratory methods, publications, events, photos, and personnel.

We identified six compounds at concentrations less than human-health benchmarks, but within a factor of 10 of those limits. Those compounds might warrant further study to understand their transport and fate within the watershed.

Measured concentrations of many compounds in water people use. Some compounds are regulated as health hazards; a few of these were over the benchmark limits. Others may become issues of concern, so studies such as this give us helpful background levels.

Links to laboratory capabilities within the USGS for paleomagnetism and paleomagnetic and rock magnetic procedures for dating and determination of magnetic direction and polarity in samples with links to techniques, equipment, and contacts.